One Pot Synthesis and Properties of Cationic Surfactants: n‐Alkyl‐3‐Methylpyridinium Bromide

Abstract

Three new amphiphilic compounds i.e., n‐decyl‐3‐methylpyridinium bromide (a), n‐dodecyl‐3‐methylpyridinium bromide (b), and n‐tetradecyl‐3‐methylpyridinium bromide (c), have been synthesized by condensation reaction and characterized by NMR (1H, 13C) and FTIR spectroscopic techniques. The micellization behavior of the compounds has been studied in ethanol employing conductometry and UV/visible spectroscopy. The critical micellization concentration (CMC) values for compound a, b and c was found to be 0.31, 0.29 and 0.27 m mol L−1, respectively. Effect of temperature on the CMC was checked in the range of 298‐318 K. The thermodynamic parameters such as ΔG, ΔH and ΔS of the micellization process of these surfactants were computed. The negative values of ΔG and positive values of ΔH indicated the spontaneous and endothermic nature of the micellization process. Antimicrobial activities of these amphiphiles showed significant activity against different bacterial strains.

Synthesis, Characterization, and Micellization Behavior of Cationic Surfactants: n‐Alkyl‐3‐Methylpyridinium Bromides and Their Drug Interaction Study by UV–Visible Spectroscopy and Conductometry

“…S7 and S8) was also studied to elaborate thermodynamic parameters of micellization. The determined thermodynamic parameters for micellization of both compounds a and b are given in Table S1 and are in good agreement with the previously determined values for similar compounds (Fayyaz et al, ). It was found that micellization is spontaneous and endothermic in nature having a negative value of Gibb's free energy and a positive value of enthalpy.…”

“…In the current work, two new surfactants, i.e., n‐hexyl‐3‐methylpyridinium bromide ( a ) and n‐octyl‐3‐methylpyridinium bromide ( b ), were synthesized and characterized as reported earlier (Fayyaz et al, ) The percent yield of compounds a and b was found to be 42% and 38%, respectively. Both a and b are soluble in H 2 O, CH 3 OH, C 2 H 5 OH, and other organic solvents.…”

“…The CMC values of both compounds were determined using ultraviolet (UV)–visible spectroscopic and conductometric methods as reported previously (Fayyaz et al, ) and the solvent used i. e., ethanol, was of analytical grade and used as such.…”

“…The compounds ( a and b ) were examined to see their antibacterial activities against four bacterial strains; two Gram‐Positive ( Bacillus subtilis (ATCC6051) and Staphylococcus aureus (ATCC6538)) and two Gram‐negative ( Escherichia coli (ATCC15224) and Enterobacteraerogenes (ATCC13048)) according to the previously reported procedure (Fayyaz et al, ). The average relative standard deviation of the outcomes was up to 2.5%.…”

“…Therefore, it is practicable to modify the length and nature of the alkyl chain attached to the nitrogen in the pyridinium ring. In continuation of our previous work (Fayyaz et al, 2016), two new n-alkyl-3-methylpyridinium surfactants were synthesized, and characterized using spectroscopic techniques like NMR ( 1 H and 13 C) and Fourier-transform infrared spectroscopy (FT-IR). Their CMC, thermodynamic parameters (ΔG, ΔH, and ΔS), and biological activity are also reported.…”